【Objectives】Si and microbial application could relieve the crop replanting problems(CRPs).We further studied the change of key microorganisms that are related to the beneficial effects,aiming at provide reference fo...【Objectives】Si and microbial application could relieve the crop replanting problems(CRPs).We further studied the change of key microorganisms that are related to the beneficial effects,aiming at provide reference for the manufacture and application of both microbial agents and Si fertilizer in food lily production.【Methods】A field experiment was conducted over a three-year period,from March 2019 to March 2022.The experimental field had been continuously cultivated with lily for 9 years.Three treatments were established:silicon fertilizer(SF),microbial agents(“Special 8^(TM)”,MF),and combined application of silicon fertilizer and microbial agents(SMF).A control group with blank soil(CK)was also included.At seedling stage of Lanzhou lilies in 2020 and 2021,the shoot and bulb dry weight,and the plant height and stem diameter of Lanzhou lilies were investigated for calculation of seedling index.In July 2020,20 plants were selected in each plot,and root zone soils were sampled at a depth of 20 cm,10 cm away from the roots,and then mixed to form a composite sample.The soil available Si and organic matter content were analyzed,and the fungal community structure and some specific microbial groups in soils were determined with high-throughput sequencing of ITS.【Results】All the three treatments significantly enhanced the lily plant growth and the seedling index,compared to CK.Besides,SF and MF treatments increased the relative abundances(RA)and diversity of fungal communities,and altered the community structures.The RA of some specific groups were found to be significantly correlated with the seedling index and/or soil available Si.Of them,the RA of the genera Fusarium,Dactylonectria,Humicola,Stilbella,and the species Humicola_grisea showed a positive correlation,while that of the genera Mortierella,Stilbella,Holtermanniella,and the species Mortierella_fatshederae showed a negative correlation with seedling index.The genera Fusarium,Stilbella,the species Humicola_grisea,and Dactylonectria_estremocensis showed a positive correlation,while the genura Stilbella,and the species Mortierella fatshederae showed a negative correlation with available Si content.In the co-occurence network of top twenty fungal genera and top sixteen bacterial genera(RA>0.2%),Holtermanniella was the only genus that interacted with the bacteria and negatively correlated with bacterial genus Blastococcus.Holtermanniella was also the most densely connected genera,followed by the genus Fusarium,Didymella and Humicola.In addition,the genus Holtermanniella was the key species connecting fungal and bacterial community in soil.Fungal functional prediction revealed that SF,MF and SMF treatments decreased plant pathogens guilds and increased the beneficial guilds Ectomycorrhizal,plant saprophyte,leaf saprophyte,and arbuscular mycorrhizal compared to CK.【Conclusions】Combined application of silicon fertilizer and microbial agents can alleviate continuous replanting problems of Lanzhou lilies through restoring the fungal community diversity,and promoting plant residue depredation,thus reducing soil born disease incidence.The beneficial genus Humicola and its one species H.grisea acts as bioconversion,and the genus Acremonium acts as plant pathogen inhibitor.展开更多
【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact ...【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact of this soaking method on the fungal and bacterial community structures using next-generation sequencing technology(NGS).【Methods】Lily bulbs were soaked in a seed treating agent containing beneficial microbes(SP treatment)for 4 hours.Subsequently,they were planted in soil in July and sampled in September to assess plant growth,rhizosphere soil physicochemical properties,and microorganism community structures.In addition,we employed the software PICRUSt and FUNGuild to predict bacterial pathways and fungal functions.【Results】Under SP treatment,there were significant alterations in fungi and bacteria community structures,accompanied by improved soil nutrient status.Notably,the relative abundance of dominant microorganism groups,such as the fungi Basidiomycota,Pseudeurotium,Cladophialophora,Microascus,and Dactylonectria,as well as the bacteria Proteobacteria,Chloroflexi,Ochrobactrium,Lysobacter,and RB41,underwent notable changes.Microorganism function prediction results indicated a reduction in pathotrophic fungi(including plant pathogens)and an increase in endophytic and saprotrophic fungi under SP treatment.Among the top 20 metabolism pathways,80%were upregulated in SP treatment compared to the CK.【Conclusions】Seed soaking with beneficial microbial strain promotes the growth of Lanzhou lily bulbs.The beneficial microorganisms play a crucial role in regulating soil microbial structures,enhancing the accumulation of endophytic fungi,reducing the abundance of pathogens,and improving soil functions.Furthermore,specific microbial groups are found to be involved in maintaining soil health.展开更多
Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by ...Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by synthesizing AAFA using original,medium-fine,and ultrafine fly ash as precursors,and then specimens were cured with a five-stage temperature-controlled microwave.The compressive strength results indicate that the original AAFA develops the highest strength initially during microwave-curing,reaching 28 MPa at stage 2.Medium-fine AAFA exhibits the highest strength of 60 MPa when cured to stage 4-I,which is 26%higher than the peak strength of original AAFA.It is attributed to the significant rise in their specific surface area,which accelerates the dissolution of Si and Al from the precursor and facilitates the subsequent formation of N-A-S-H gels.Additionally,nanoscale zeolite crystals formed as secondary products fill the tiny gaps between amorphous products,thereby significantly improving their microstructure.In contrast,ultrafine fly ash,primarily composed of fragmented particles,necessitated a substantial amount of water,which adversely affects the absorption efficiency for microwave of AAFA specimens.Thus,ultrafine AAFA specimens consistently exhibit the lowest compressive strength.Specifically,at the end of curing,the compressive strength of these three specimens with microwave-curing is approximately 32%,59%,and 172%higher than that of the steam-cured sample,respectively.These findings demonstrate the compatibility of microwave-curing and fly ash refinement in enhancing the early compressive strength development of AAFA.展开更多
Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various f...Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various factors affect roots reinforcement during seismic loading have rarely been studied.The objective is to conduct a series of cyclic direct simple shear tests and DEM numerical simulation to investigate the cyclic behaviour of rooted loess.The effects of initial static shear stress and loading frequency on the cyclic resistance of root-soil composites were first investigated.After that,cyclic direct simple shear simulations at constant volume were carried out based on the discrete element method(PFC^(3D))to investigate the effects of root geome-try,mechanical traits and root-soil bond strength on the cyclic strength of rooted loess.It was discovered that the roots could effectively improve the cyclic resistance of loess.The cyclic resistance of the root-soil composite decreases with the increase of the initial shear stress,then increases,and improves with the increase of the frequency.The simulation result show that increases in root elastic modulus and root-soil interfacial bond strength can all enhance the cyclic resistance of root-soil composites,and the maximum cyclic resistance of the root-soil composite was obtained when the initial inclination angle of the root system was 90°.展开更多
In order to expand the advantages of strong durability and high compressive strength of calcium silicate hydrates(C-S-H),at the same time to make up for the poor early mechanical strength of magnesium silicate hydrate...In order to expand the advantages of strong durability and high compressive strength of calcium silicate hydrates(C-S-H),at the same time to make up for the poor early mechanical strength of magnesium silicate hydrates (M-S-H),we present the features and advantages of C-S-H and M-S-H and a comprehensive review of the progress on CaO-MgO-SiO_(2)-H_(2)O.Moreover,we systematically describe natural calcium and magnesium silicate minerals and thermodynamic properties of CaO-MgO-SiO_(2)-H_(2)O.The effect of magnesium on C-S-H and calcium on M-S-H is summarized deeply;the formation and structural feature of CaO-MgO-SiO_(2)-H_(2)O is also explained in detail.Finally,the development of calcium and magnesium silicate hydrates in the future is pointed out,and the further research is discussed and estimated.展开更多
The SrCO3/AgI photocatalysts were prepared via a co-precipitation method by using SrCO3 as a co-photocatalyst and AgI as a photo sensitizer.X-ray diffraction,field emission scanning electron microscope,X-ray photoelec...The SrCO3/AgI photocatalysts were prepared via a co-precipitation method by using SrCO3 as a co-photocatalyst and AgI as a photo sensitizer.X-ray diffraction,field emission scanning electron microscope,X-ray photoelectron spectrometer,UV-vis diffuse reflectance spectroscopy and electrochemical impedance spectroscope were used to analyze the structure,micro-morphology,chemical compositions,optical properties and photo-generated carrier behaviors of the as-prepared samples,respectively.The photocatalytic degradation mechanism of the as-developed composites was also proposed.Analysis results show SrCO3,an insulator,can improve the photocatalytic performances and recyclability of AgI for degrading tetracycline under visible light.As the theoretical molar ratio of Sr(NO3)2 to AgNO3 increases,the degradation efficiency of the hybrids first increases and then descends.When the theoretical molar ratio of that is 1:1,it acquires the maximum of 66.6% within 8 min.This is higher than 32.0% of pure AgI and 34.0% of SrCO3.Moreover,after three times degradations it is 63.0%,which is higher than 13.6% of AgI.The improvement of the photocatalytic performance of the sample is attributed to the construction of hybrids.The main activated species in catalysis process are superoxide radicals.展开更多
SnO2/AgIO4 hybrids were fabricated by an in-situ synthetic method at room temperature. The structure, morphology, light response range, separation efficiency of the electron-hole pairs and elements of the as-synthesiz...SnO2/AgIO4 hybrids were fabricated by an in-situ synthetic method at room temperature. The structure, morphology, light response range, separation efficiency of the electron-hole pairs and elements of the as-synthesized samples were characterized by adopting X-ray diffraction, scanning electron microscopy, UV-Vis diffuse reflectance spectroscopy, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy, respectively. The synergistically photocatalytic degradation mechanism of the as-synthesized composites was also proposed. The experimental results reveal that under the visible light irradiation the as-synthesized SnO2/AgIO4 hybrids can enhance the photocatalytic degradation efficiency of rhodamine B compared to pure samples. With increasing the molar ratios of AgIO4 to SnO2, it displays the trend of first increasing and then decreasing. When it is 1:2 in 150 min, the as-prepared hybrids have the highest degradation efficiency of 93.1%, which increases by 6550.0%, 30.5%, and 1505.0% compared to those of pure SnO2, AgIO4, and TiO2(P25), respectively. Moreover, the Sn-O-Ag cross-linking bonds are formed at the interfaces of SnO2 and AgIO4. In addition, superoxide anion radicals and holes play a major role in the process of photodegradation.展开更多
目的探讨河南省结核杆菌的遗传多样性。方法使用26位点(经典24位点和其他2位点)的分支杆菌散在重复单元中数目可变串联重复序列(mycobacterium interspersed repetitive unit-variable number tandem repeat,MIRU-VNTR)和间隔区寡核苷...目的探讨河南省结核杆菌的遗传多样性。方法使用26位点(经典24位点和其他2位点)的分支杆菌散在重复单元中数目可变串联重复序列(mycobacterium interspersed repetitive unit-variable number tandem repeat,MIRU-VNTR)和间隔区寡核苷酸分型(spoligotyping)对来自2015年期间河南省不同地区的668株结核杆菌分离株进行分型分析。对结核菌spoligotype类型和耐药表型的相关性进行分析。结果 Spoligotyping分析表明668株结核杆菌被分到10个不同的基因簇中。北京家族基因型是河南地区结核杆菌中的优势菌株。北京家族基因型菌株对四种一线药全耐药以及耐多药菌株比例明显高于非北京型菌株。668株结核杆菌通过26位点VNTR被分为567个不同的基因型。26个位点中15个位点具有高度或适中的分辨能力。10个分辨能力最强位点的组合分辨力能与26位点相当。结论北京家族是河南省最流行的结核杆菌基因型。10位点VNTR和spoligotyping相结合可有效地用于河南省结核杆菌进化遗传学研究。展开更多
Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the applicatio...Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the application scenarios,operational modes,services supported by 5G-R terminals,and the data paths between these terminals and the connected railway application service systems.Further analysis concentrates on the security risks posed by the characteristics of intelligent 5G-R handheld terminals,lightweight Internet of Things(IoT)communication terminals,and onboard integrated wireless transmission equipment with public-private convergence.In light of the risks above,this paper presents the terminal security control requirements.Furthermore,based on the planned architecture of the 5G-R system and security technologies such as terminal identity authentication and behavior auditing,the paper proposes a solution package for the 5G-R terminal security control system,including the overall architecture,functional implementation,and interface configuration.These solutions aim to achieve unified control over the admission and access of 5G-R handheld terminals,IoT communication terminals,and onboard integrated wireless communication equipment to railway application systems.Additionally,they enable the security control and analysis of terminal behaviors and application data,facilitate the security management of terminals,and ensure the secure release,download,and installation of mobile applications.展开更多
Urban geological information platforms have traditionally focused on static data provision for public service,constrained by funding and limited engagement with engineering applications.This study takes Hangzhou-a maj...Urban geological information platforms have traditionally focused on static data provision for public service,constrained by funding and limited engagement with engineering applications.This study takes Hangzhou-a major Chinese megacity-as a model to propose a technically integrated platform that aligns with urban infrastructure development,particularly underground space engineering.Through the adoption of the large-scale relational database system Oracle,we first established a comprehensive storage framework for fundamental urban geological and underground infrastructure information,thereby completed the construction of the core databases.To ensure spatial consistency across multi-source data and to meet the platform’s high computational demands while improving overall server responsiveness,we introduced three critical innovations:voxel-based model encoding,distributed computing,and frontend-backend separation with asynchronous processing.To align with urban engineering projects and enhance economic returns,the platform was initially developed through the integration of foundational geological data,including borehole records and aboveground-underground spatial information.Based on this foundation,its practical application in Hangzhou’s Qiantang New Town further demonstrated the platform’s potential in supporting subway routing,underground structure planning,and engineering cost analysis.Consequently,the construction of the Hangzhou geological information platform not only offers robust support for urban decision-making and smart city development but also provides a replicable model for addressing the technical and institutional challenges commonly encountered in the development of urban geological platforms.展开更多
By using the phased characteristics summarizing method of the existing research on magnesium slag,this study investigates the hydration reaction,alkali activation reaction and CO_(2) mineralization reaction processes ...By using the phased characteristics summarizing method of the existing research on magnesium slag,this study investigates the hydration reaction,alkali activation reaction and CO_(2) mineralization reaction processes and mechanisms,and then explores its high-value utilization.The results show that physical and chemical activation can improve the mechanical properties of the gelled material system by increasing the crystal phase defects and surface energy and by reconstructing a new gelling system by depolymerizing glass.The CO_(2) mineralization reaction of magnesium slag can be used to construct a new gelling system for CaCO_(3) and calcium-modified silica gel.Magnesium slag can also be used to enhance the dry shrinkage and carbonation resistance of concrete owing to its expansibility and high alkali reserves.The mechanism and existence form of heavy metal ions in magnesium slag have been clarified.The study proposed a production system for magnesium slag and highlighted the potential research value in the field of wet carbonation to promote the application of magnesium slag.展开更多
Amid China’s rapid economic growth,significant regional imbalances persisted.To address this disparity,it is essential to pursue high-quality development by fostering endogenous drivers within poverty-stricken areas....Amid China’s rapid economic growth,significant regional imbalances persisted.To address this disparity,it is essential to pursue high-quality development by fostering endogenous drivers within poverty-stricken areas.In late 2011,the Chinese government introduced a new nationwide regional poverty alleviation and development program.This study examines the macroeconomic impacts and micro-level mechanisms of these policies by leveraging manually compiled policy documents and macro and micro data(county economies,enterprises,and land transactions),using a DID approach.The findings reveal that the program significantly boosted economic growth in poor regions without causing negative spillovers to neighboring or paired-assistance areas.Economic growth in the assisted regions was primarily driven by industrialization,encompassing both scale expansion and efficiency gains.A cost-benefit analysis further confirms substantial economic returns and long-term fiscal sustainability.These results provide important policy implications for refining regional poverty policies and advancing balanced development.展开更多
基金Key Research project of Gansu Province of China(22YF7NA108)National Natural Science Foundation of China(31860549)+1 种基金Industry Supporting Project from Education Department of Gansu Province(2023CYZC-49)Major Science and Technology project of Gansu province(24ZDNA006)。
文摘【Objectives】Si and microbial application could relieve the crop replanting problems(CRPs).We further studied the change of key microorganisms that are related to the beneficial effects,aiming at provide reference for the manufacture and application of both microbial agents and Si fertilizer in food lily production.【Methods】A field experiment was conducted over a three-year period,from March 2019 to March 2022.The experimental field had been continuously cultivated with lily for 9 years.Three treatments were established:silicon fertilizer(SF),microbial agents(“Special 8^(TM)”,MF),and combined application of silicon fertilizer and microbial agents(SMF).A control group with blank soil(CK)was also included.At seedling stage of Lanzhou lilies in 2020 and 2021,the shoot and bulb dry weight,and the plant height and stem diameter of Lanzhou lilies were investigated for calculation of seedling index.In July 2020,20 plants were selected in each plot,and root zone soils were sampled at a depth of 20 cm,10 cm away from the roots,and then mixed to form a composite sample.The soil available Si and organic matter content were analyzed,and the fungal community structure and some specific microbial groups in soils were determined with high-throughput sequencing of ITS.【Results】All the three treatments significantly enhanced the lily plant growth and the seedling index,compared to CK.Besides,SF and MF treatments increased the relative abundances(RA)and diversity of fungal communities,and altered the community structures.The RA of some specific groups were found to be significantly correlated with the seedling index and/or soil available Si.Of them,the RA of the genera Fusarium,Dactylonectria,Humicola,Stilbella,and the species Humicola_grisea showed a positive correlation,while that of the genera Mortierella,Stilbella,Holtermanniella,and the species Mortierella_fatshederae showed a negative correlation with seedling index.The genera Fusarium,Stilbella,the species Humicola_grisea,and Dactylonectria_estremocensis showed a positive correlation,while the genura Stilbella,and the species Mortierella fatshederae showed a negative correlation with available Si content.In the co-occurence network of top twenty fungal genera and top sixteen bacterial genera(RA>0.2%),Holtermanniella was the only genus that interacted with the bacteria and negatively correlated with bacterial genus Blastococcus.Holtermanniella was also the most densely connected genera,followed by the genus Fusarium,Didymella and Humicola.In addition,the genus Holtermanniella was the key species connecting fungal and bacterial community in soil.Fungal functional prediction revealed that SF,MF and SMF treatments decreased plant pathogens guilds and increased the beneficial guilds Ectomycorrhizal,plant saprophyte,leaf saprophyte,and arbuscular mycorrhizal compared to CK.【Conclusions】Combined application of silicon fertilizer and microbial agents can alleviate continuous replanting problems of Lanzhou lilies through restoring the fungal community diversity,and promoting plant residue depredation,thus reducing soil born disease incidence.The beneficial genus Humicola and its one species H.grisea acts as bioconversion,and the genus Acremonium acts as plant pathogen inhibitor.
文摘【Background】The application of beneficial-microbial seed soaking prior to sowing represents a novel technology that has not been employed in Lanzhou lily cultivation.We conducted an experiment to explore the impact of this soaking method on the fungal and bacterial community structures using next-generation sequencing technology(NGS).【Methods】Lily bulbs were soaked in a seed treating agent containing beneficial microbes(SP treatment)for 4 hours.Subsequently,they were planted in soil in July and sampled in September to assess plant growth,rhizosphere soil physicochemical properties,and microorganism community structures.In addition,we employed the software PICRUSt and FUNGuild to predict bacterial pathways and fungal functions.【Results】Under SP treatment,there were significant alterations in fungi and bacteria community structures,accompanied by improved soil nutrient status.Notably,the relative abundance of dominant microorganism groups,such as the fungi Basidiomycota,Pseudeurotium,Cladophialophora,Microascus,and Dactylonectria,as well as the bacteria Proteobacteria,Chloroflexi,Ochrobactrium,Lysobacter,and RB41,underwent notable changes.Microorganism function prediction results indicated a reduction in pathotrophic fungi(including plant pathogens)and an increase in endophytic and saprotrophic fungi under SP treatment.Among the top 20 metabolism pathways,80%were upregulated in SP treatment compared to the CK.【Conclusions】Seed soaking with beneficial microbial strain promotes the growth of Lanzhou lily bulbs.The beneficial microorganisms play a crucial role in regulating soil microbial structures,enhancing the accumulation of endophytic fungi,reducing the abundance of pathogens,and improving soil functions.Furthermore,specific microbial groups are found to be involved in maintaining soil health.
文摘Microwave-curing and mechanical grinding of fly ash have both beenadopted as effective methods for improving the early-age strength of alkali-activated fly ash(AAFA)binders.This study combined these two approaches by synthesizing AAFA using original,medium-fine,and ultrafine fly ash as precursors,and then specimens were cured with a five-stage temperature-controlled microwave.The compressive strength results indicate that the original AAFA develops the highest strength initially during microwave-curing,reaching 28 MPa at stage 2.Medium-fine AAFA exhibits the highest strength of 60 MPa when cured to stage 4-I,which is 26%higher than the peak strength of original AAFA.It is attributed to the significant rise in their specific surface area,which accelerates the dissolution of Si and Al from the precursor and facilitates the subsequent formation of N-A-S-H gels.Additionally,nanoscale zeolite crystals formed as secondary products fill the tiny gaps between amorphous products,thereby significantly improving their microstructure.In contrast,ultrafine fly ash,primarily composed of fragmented particles,necessitated a substantial amount of water,which adversely affects the absorption efficiency for microwave of AAFA specimens.Thus,ultrafine AAFA specimens consistently exhibit the lowest compressive strength.Specifically,at the end of curing,the compressive strength of these three specimens with microwave-curing is approximately 32%,59%,and 172%higher than that of the steam-cured sample,respectively.These findings demonstrate the compatibility of microwave-curing and fly ash refinement in enhancing the early compressive strength development of AAFA.
文摘Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various factors affect roots reinforcement during seismic loading have rarely been studied.The objective is to conduct a series of cyclic direct simple shear tests and DEM numerical simulation to investigate the cyclic behaviour of rooted loess.The effects of initial static shear stress and loading frequency on the cyclic resistance of root-soil composites were first investigated.After that,cyclic direct simple shear simulations at constant volume were carried out based on the discrete element method(PFC^(3D))to investigate the effects of root geome-try,mechanical traits and root-soil bond strength on the cyclic strength of rooted loess.It was discovered that the roots could effectively improve the cyclic resistance of loess.The cyclic resistance of the root-soil composite decreases with the increase of the initial shear stress,then increases,and improves with the increase of the frequency.The simulation result show that increases in root elastic modulus and root-soil interfacial bond strength can all enhance the cyclic resistance of root-soil composites,and the maximum cyclic resistance of the root-soil composite was obtained when the initial inclination angle of the root system was 90°.
基金Funded by Natural Science Basic Research Plan in Shaanxi Province of China (Nos.2021JQ-500, 2021GY-203, 2023-JCYB-096)Shaanxi Provincial Education Department of Key Scientific Research Plan (No.20JS079)Shaanxi Provincial Education Department of Normal Scientific Research Plan (No.20JK0727)。
文摘In order to expand the advantages of strong durability and high compressive strength of calcium silicate hydrates(C-S-H),at the same time to make up for the poor early mechanical strength of magnesium silicate hydrates (M-S-H),we present the features and advantages of C-S-H and M-S-H and a comprehensive review of the progress on CaO-MgO-SiO_(2)-H_(2)O.Moreover,we systematically describe natural calcium and magnesium silicate minerals and thermodynamic properties of CaO-MgO-SiO_(2)-H_(2)O.The effect of magnesium on C-S-H and calcium on M-S-H is summarized deeply;the formation and structural feature of CaO-MgO-SiO_(2)-H_(2)O is also explained in detail.Finally,the development of calcium and magnesium silicate hydrates in the future is pointed out,and the further research is discussed and estimated.
基金Funded by the Natural Science Foundation of Hebei Province,China(Nos.E2019210251 and B2019210331)the Innovation Ability Improvement Project of Hebei Province,China(No.20543601D)the Ministry of Education"Chun Hui Plan"Cooperative Research Project,China。
文摘The SrCO3/AgI photocatalysts were prepared via a co-precipitation method by using SrCO3 as a co-photocatalyst and AgI as a photo sensitizer.X-ray diffraction,field emission scanning electron microscope,X-ray photoelectron spectrometer,UV-vis diffuse reflectance spectroscopy and electrochemical impedance spectroscope were used to analyze the structure,micro-morphology,chemical compositions,optical properties and photo-generated carrier behaviors of the as-prepared samples,respectively.The photocatalytic degradation mechanism of the as-developed composites was also proposed.Analysis results show SrCO3,an insulator,can improve the photocatalytic performances and recyclability of AgI for degrading tetracycline under visible light.As the theoretical molar ratio of Sr(NO3)2 to AgNO3 increases,the degradation efficiency of the hybrids first increases and then descends.When the theoretical molar ratio of that is 1:1,it acquires the maximum of 66.6% within 8 min.This is higher than 32.0% of pure AgI and 34.0% of SrCO3.Moreover,after three times degradations it is 63.0%,which is higher than 13.6% of AgI.The improvement of the photocatalytic performance of the sample is attributed to the construction of hybrids.The main activated species in catalysis process are superoxide radicals.
基金Funded by the Natural Science Foundation of Hebei Province,China(No.E2019210251)the National Natural Science Foundation of China(No.51778378)
文摘SnO2/AgIO4 hybrids were fabricated by an in-situ synthetic method at room temperature. The structure, morphology, light response range, separation efficiency of the electron-hole pairs and elements of the as-synthesized samples were characterized by adopting X-ray diffraction, scanning electron microscopy, UV-Vis diffuse reflectance spectroscopy, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy, respectively. The synergistically photocatalytic degradation mechanism of the as-synthesized composites was also proposed. The experimental results reveal that under the visible light irradiation the as-synthesized SnO2/AgIO4 hybrids can enhance the photocatalytic degradation efficiency of rhodamine B compared to pure samples. With increasing the molar ratios of AgIO4 to SnO2, it displays the trend of first increasing and then decreasing. When it is 1:2 in 150 min, the as-prepared hybrids have the highest degradation efficiency of 93.1%, which increases by 6550.0%, 30.5%, and 1505.0% compared to those of pure SnO2, AgIO4, and TiO2(P25), respectively. Moreover, the Sn-O-Ag cross-linking bonds are formed at the interfaces of SnO2 and AgIO4. In addition, superoxide anion radicals and holes play a major role in the process of photodegradation.
文摘目的探讨河南省结核杆菌的遗传多样性。方法使用26位点(经典24位点和其他2位点)的分支杆菌散在重复单元中数目可变串联重复序列(mycobacterium interspersed repetitive unit-variable number tandem repeat,MIRU-VNTR)和间隔区寡核苷酸分型(spoligotyping)对来自2015年期间河南省不同地区的668株结核杆菌分离株进行分型分析。对结核菌spoligotype类型和耐药表型的相关性进行分析。结果 Spoligotyping分析表明668株结核杆菌被分到10个不同的基因簇中。北京家族基因型是河南地区结核杆菌中的优势菌株。北京家族基因型菌株对四种一线药全耐药以及耐多药菌株比例明显高于非北京型菌株。668株结核杆菌通过26位点VNTR被分为567个不同的基因型。26个位点中15个位点具有高度或适中的分辨能力。10个分辨能力最强位点的组合分辨力能与26位点相当。结论北京家族是河南省最流行的结核杆菌基因型。10位点VNTR和spoligotyping相结合可有效地用于河南省结核杆菌进化遗传学研究。
文摘Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the application scenarios,operational modes,services supported by 5G-R terminals,and the data paths between these terminals and the connected railway application service systems.Further analysis concentrates on the security risks posed by the characteristics of intelligent 5G-R handheld terminals,lightweight Internet of Things(IoT)communication terminals,and onboard integrated wireless transmission equipment with public-private convergence.In light of the risks above,this paper presents the terminal security control requirements.Furthermore,based on the planned architecture of the 5G-R system and security technologies such as terminal identity authentication and behavior auditing,the paper proposes a solution package for the 5G-R terminal security control system,including the overall architecture,functional implementation,and interface configuration.These solutions aim to achieve unified control over the admission and access of 5G-R handheld terminals,IoT communication terminals,and onboard integrated wireless communication equipment to railway application systems.Additionally,they enable the security control and analysis of terminal behaviors and application data,facilitate the security management of terminals,and ensure the secure release,download,and installation of mobile applications.
基金supported by the China Geological Survey,Nanjing Center,Zhejiang Geological Survey and China University of Geosciences,Wuhanfunded by the Laboratory of Geological Safety of Underground Space in Coastal Cities,Ministry of Natural Resources(Project No.BHKF2023×01)the China Geological Survey,Nanjing Center(Project No.DD20190281).
文摘Urban geological information platforms have traditionally focused on static data provision for public service,constrained by funding and limited engagement with engineering applications.This study takes Hangzhou-a major Chinese megacity-as a model to propose a technically integrated platform that aligns with urban infrastructure development,particularly underground space engineering.Through the adoption of the large-scale relational database system Oracle,we first established a comprehensive storage framework for fundamental urban geological and underground infrastructure information,thereby completed the construction of the core databases.To ensure spatial consistency across multi-source data and to meet the platform’s high computational demands while improving overall server responsiveness,we introduced three critical innovations:voxel-based model encoding,distributed computing,and frontend-backend separation with asynchronous processing.To align with urban engineering projects and enhance economic returns,the platform was initially developed through the integration of foundational geological data,including borehole records and aboveground-underground spatial information.Based on this foundation,its practical application in Hangzhou’s Qiantang New Town further demonstrated the platform’s potential in supporting subway routing,underground structure planning,and engineering cost analysis.Consequently,the construction of the Hangzhou geological information platform not only offers robust support for urban decision-making and smart city development but also provides a replicable model for addressing the technical and institutional challenges commonly encountered in the development of urban geological platforms.
基金Funded by the National Natural Science Foundation of China(No.52208203)China Postdoctoral Science Foundation Funded Project(No.2023MD734209)+2 种基金Shaanxi Province Key Research and Development Program Project(No.2024GH-YBXM-03)Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(No.23JP081)Innovation and Entrepreneurship Training Program for College Students(No.S202310703)。
文摘By using the phased characteristics summarizing method of the existing research on magnesium slag,this study investigates the hydration reaction,alkali activation reaction and CO_(2) mineralization reaction processes and mechanisms,and then explores its high-value utilization.The results show that physical and chemical activation can improve the mechanical properties of the gelled material system by increasing the crystal phase defects and surface energy and by reconstructing a new gelling system by depolymerizing glass.The CO_(2) mineralization reaction of magnesium slag can be used to construct a new gelling system for CaCO_(3) and calcium-modified silica gel.Magnesium slag can also be used to enhance the dry shrinkage and carbonation resistance of concrete owing to its expansibility and high alkali reserves.The mechanism and existence form of heavy metal ions in magnesium slag have been clarified.The study proposed a production system for magnesium slag and highlighted the potential research value in the field of wet carbonation to promote the application of magnesium slag.
基金Supported by the National Natural Science Foundation of China(NSFC)(Grant No.72173131)for“Research on New Trends and Driving Forces in China’s Labor Income Share:A Micro Perspective Based on Enterprise Behavior”the China Postdoctoral Science Foundation(Grant No.2023M743940)for“Research on the Income Distribution Effects of Transport Infrastructure Construction:Theoretical Analysis and Quantitative Assessment”.
文摘Amid China’s rapid economic growth,significant regional imbalances persisted.To address this disparity,it is essential to pursue high-quality development by fostering endogenous drivers within poverty-stricken areas.In late 2011,the Chinese government introduced a new nationwide regional poverty alleviation and development program.This study examines the macroeconomic impacts and micro-level mechanisms of these policies by leveraging manually compiled policy documents and macro and micro data(county economies,enterprises,and land transactions),using a DID approach.The findings reveal that the program significantly boosted economic growth in poor regions without causing negative spillovers to neighboring or paired-assistance areas.Economic growth in the assisted regions was primarily driven by industrialization,encompassing both scale expansion and efficiency gains.A cost-benefit analysis further confirms substantial economic returns and long-term fiscal sustainability.These results provide important policy implications for refining regional poverty policies and advancing balanced development.
